Spring seat assembly

ABSTRACT

A vehicle suspension system including a pair of spring seat retainers. One of the spring seat retainers includes a flange and a pocket portion extending from the flange to a distal rim. A jounce bumper is mounted to the pocket portion of the spring seat retainer and extends from the rim. A band encircles the rim for preventing deformation of the rim upon compression of the jounce bumper.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. provisional patent application Ser. No. 60/620,590, which was filed on Oct. 20, 2004.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an assembly for a suspension system of a vehicle of the type using a coil spring isolator.

2. Description of the Prior Art

Vehicle suspension systems of the prior art typically include spring seat assemblies each having a pair of opposing spring seat retainers with a coil spring disposed therebetween. Spring seat retainers of a variety of configurations are well known in the art. An example of a configuration of a spring seat retainer is shown in European Publication No. 0 778 166 B1. The spring seat retainer disclosed in this European Publication is formed of a polymeric material and includes a flange extending radially from a central axis. A pocket portion extends axially from the flange to a distal rim for defining a groove to support a coil spring encircling the pocket portion. The pocket portion also defines a cavity for supporting a jounce bumper. The design and material considerations of the spring seat retainer disclosed in the European Publication provides significant advantages over other prior art retainers.

During operation, the coil spring can be compressed to the point where the jounce bumper engages an opposing spring seat retainer to cause the jounce bumper to compress and exert forces radially outwardly against the rim. These radial forces on the rim can be large enough to cause the rim to deform or bulge, especially if the rim is made out of the polymeric material, i.e., plastic. The functionality of the spring seat retainer can be lost after the rim radially stretches and permanently deforms the cavity, which can cause the jounce bumper to fall out of the cavity.

Accordingly, it would be desirable to develop a spring seat retainer that incorporates the advantages of the prior art retainers while avoiding the potential drawbacks of these retainers.

SUMMARY OF THE INVENTION AND ADVANTAGES

The invention provides a spring seat assembly for a suspension system of a vehicle utilizing a coil spring. The spring seat assembly comprises a spring seat retainer having a flange extending radially from a central axis and a pocket portion extending axially from the flange to a distal rim for supporting one end of the coil spring encircling the pocket portion. The distal rim of the pocket portion defines a distal end and a cavity between the distal end and the flange for mounting a jounce bumper within the cavity. The jounce bumper extends from the distal end for compressing and exerting radial forces within the cavity against the rim upon a predetermined compression of the coil spring. A band encircles the rim of the pocket portion for preventing deformation of the rim under the band thereby retaining the jounce bumper in the cavity upon the predetermined compression of the coil spring.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a cross-sectional view of a suspension system;

FIG. 2 is a perspective view of a first spring seat retainer engaging a coil spring;

FIG. 3 is an exploded view of the first spring seat retainer;

FIG. 4 is a perspective view of the first spring seat retainer;

FIG. 5 is a side view of the first spring seat retainer; and

FIG. 6 is a cross-sectional view of the suspension system in a compressed state.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, a suspension system 18 for a vehicle (not shown) of the type with which the instant invention is utilized is generally shown in FIG. 1. The suspension system 18 includes a spring seat assembly, a plurality of spring seats 26, and a coil spring 24. Each of the spring seats 26 include a planar portion and a protrusions 16 extending from the corresponding planar portion. The spring seats 26 are preferably made of steel and are mounted to corresponding structures (not shown) of the vehicle. The coil spring 24 is shown for illustrative purposes in phantom and does not form part of the claimed invention.

The spring seat assembly includes a first spring seat retainer 20 and a second spring seat retainer 22 wherein the first and second spring retainers 20, 22 define corresponding chambers (not numbered) for mating with corresponding protrusions 16 of the spring seats 26. In particular, the first and second spring seat retainers 20, 22 are mounted to associated spring seats 26 having the coil spring 24 disposed therebetween. One skilled in the art will appreciate that the first and second spring seat retainers 20, 22 may be of any suitable configuration to mount to alternative spring seats and/or alternative suspension systems.

Referring also to FIGS. 2-5, the first spring seat retainer 20 is shown having a flange 28 extending radially from a central axis 14 and a pocket portion or neck 30 extending axially from the flange 28 to a distal rim 32 for supporting the coil spring 24 encircling the pocket portion 30. Preferably, the flange 28 and the pocket portion 30 are formed of a homogeneous material. Even more preferably, the first spring seat retainer 20 may be formed of a polymeric material or plastic material such as nylon, isoprene, polypropylene, or polyurethane. Preferably, the first spring seat retainer 20 is formed of a one-piece integrated thermoplastic polyurethane (TPU) material.

A plurality of ribs 48 are spaced circumferentially about an exterior of the pocket portion 30 for engaging and retaining the coil spring 24. The ribs 48 extend axially from a predetermined distance spaced from the flange 28 to a shoulder 44. The ribs 48 are preferably integral with the pocket portion 30.

The distal rim 32 of the pocket portion 30 defines a distal end 72 and a cavity 34 (see FIG. 3) between the distal end 72 and the flange 28. The rim 32 also defines an inner surface and an outer surface with the outer surface defining a recess 42 extending axially from the distal end 72 to the shoulder 44. The distal end 72 of the rim 32 flows over the recess 42 to form a projection 46 extending radially outwardly. The rim 32 includes a plurality of tabs 52 disposed about the inner surface of the rim 32 and projecting in the cavity 34. The tabs 52 are preferably integral with the inner surface of the rim 32. The first spring seat retainer 20 further includes a stem 58 disposed in the cavity 34 of the rim 32.

The rim 32 can undergo undesirable bulging and other deformation from heat and pressure. The subject invention therefore includes a restrictor 40 at least partially disposed about the rim 32 of the pocket portion 30, which operates as an anti-bulging device for preventing bulging of the rim 32. The restrictor 40 preferably includes a band 40 encircling the rim 32 for preventing bulging of the rim 32 under the band 40. The band 40 is preferably continuous, presents spaced edges, and is disposed in the recess 42 with one of the edges abutting the shoulder 44. The projection 46 extends over the other edge of the band 40 opposite the shoulder 44 to retain the band 40 in the recess 42. Hence, the band 40 encircles the rim 32 of the pocket portion 30 for preventing deformation of the rim 32 under the band 40. The band 40 is preferably made of a metal, such as steel, and has a modulus of elasticity higher than the modulus of elasticity of the polymeric material of the pocket portion 30.

A spring isolator 36 abuts the flange 28 of the first spring seat retainer 20. The spring isolator 36 preferably has a donut shaped configuration complementary to the configuration of the flange 28. Preferably, the spring isolator 36 is formed of an elastomeric material, such as micro-cellular polyurethane (MPU).

A jounce bumper 38 is disposed in the cavity 34 of the pocket portion 30 and extends from the distal end 72. The jounce bumper 38 will compress and exert radial forces within the cavity 34 against the rim 32 upon a predetermined compression of the coil spring 24. Preferably, the jounce bumper 38 is formed of a polymeric or elastomeric material, such as micro-cellular polyurethane (MPU). The jounce bumper 38 includes an annular groove 50 in which the tabs 52 of the rim 32 engage the groove 50 for retaining the jounce bumper 38 in the cavity 34. As shown in FIG. 1, the jounce bumper 38 presents a hollow 54 in the bottom thereof to define a skirt 56 in which the stem 58 of the rim 32 engages the skirt 56 for forcing the jounce bumper 38 radially outwardly toward the rim 32 and into engagement with the tabs 52.

As shown in FIG. 6, the coil spring 24 can be compressed to the point where the jounce bumper 38 hits the second spring seat retainer 22 which causes the jounce bumper 38 to compress and exert forces radially outwardly against the rim 32. The band 40 resists any radial deflection of the rim 32 such that the tabs 52 of the inner surface of the rim 32 remain in continuous contact with the groove 50 to retain the jounce bumper 38 in the first spring seat retainer 20.

Referring to FIGS. 1 and 6, the second spring seat retainer 22 has a similar configuration as the first spring seat retainer 20 with a base portion 60 extending radially from the central axis 14 and a neck portion 62 extending axially from the base portion 60 for supporting the coil spring 24 encircling the neck portion 62. The second spring seat retainer 22 may be similarly formed of a polymeric material or plastic material such as nylon, isoprene, polypropylene, or polyurethane. Preferably, the second spring seat retainer 22 is similarly formed of a one-piece integrated TPU material.

A plurality of radially projecting ridges 64 are spaced about the base portion 60 and are spaced a predetermined distance from the neck portion 62 to define a depression 70 for engaging and retaining the coil spring 24. The ridges 64 are preferably integral with the base portion 60.

The neck portion 62 includes a cap at a top thereof to define a jounce contact surface 66 for engagement with the jounce bumper 38. A plurality of strips 68 are spaced circumferentially about an exterior of the neck portion 62. The strips 68 extend axially a predetermined distance spaced from the base portion 60 to a predetermined distance spaced from the jounce contact surface 66 for engaging and retaining the coil spring 24. The cap and the strips 68 are preferably integral with the neck portion 62.

The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than is specifically described. 

1. A spring seat assembly for a suspension system of a vehicle utilizing a coil spring, said assembly comprising: a spring seat retainer having a flange extending radially from a central axis and a pocket portion extending axially from said flange to a distal rim for encircling said pocket portion, and said distal rim of said pocket portion defining a distal end and a cavity between said distal end and said flange; a jounce bumper mounted to said pocket portion within said cavity and extending from said distal end for compressing and exerting radial forces within said cavity against said rim upon a predetermined compression of the coil spring, and a restrictor at least partially disposed about said rim of said pocket portion for preventing bulging of said rim to retain said jounce bumper in said cavity upon the predetermined compression of the coil spring.
 2. An assembly as set forth in claim 1 wherein said restrictor includes a band encircling said rim for preventing bulging of said rim under said band.
 3. An assembly as set forth in claim 2 wherein said band is continuously disposed about said rim.
 4. An assembly as set forth in claim 2 wherein said band has a modulus of elasticity that is higher than a modulus of elasticity of said pocket portion.
 5. An assembly as set forth in claim 4 wherein said pocket portion is formed of a polymeric material and said band is formed of a metallic material.
 6. An assembly as set forth in claim 1 wherein said pocket portion and said flange are formed of a homogeneous material.
 7. An assembly as set forth in claim 1 wherein said pocket portion and said flange are formed of a polymeric material.
 8. An assembly as set forth in claim 7 wherein said polymeric material of said pocket portion and said flange is further defined as a thermoplastic polyurethane material.
 9. An assembly as set forth in claim 2 wherein said rim defines an inner surface and an outer surface with said outer surface defining a recess extending axially from said distal end to a shoulder and said band presents spaced edges and is disposed in said recess with one of said edges abutting said shoulder.
 10. An assembly as set forth in claim 9 wherein said distal end of said rim includes a protrusion extending over one of said edges of said band opposite said shoulder to retain said band in said recess.
 11. An assembly as set forth in claim 1 further including ribs spaced about said pocket portion for engaging the coil spring, said ribs extending axially to said shoulder of said recess.
 12. An assembly as set forth in claim 1 further including a spring isolator abutting said flange of said spring seat retainer.
 13. An assembly as set forth in claim 12 wherein said spring isolator extends radially from said pocket portion to an outer edge of said flange.
 14. An assembly as set forth in claim 12 wherein said spring isolator is formed of an elastomeric material.
 15. An assembly as set forth in claim 14 wherein said elastomeric material of said spring isolator is further defined as micro-cellular polyurethane.
 16. An assembly as set forth in claim 1 wherein said spring seat retainer is further defined as a first spring seat retainer and further including a second spring seat retainer.
 17. An assembly as set forth in claim 16 wherein said second spring seat retainer includes a base portion extending radially from a central axis and a neck portion extending axially from said base portion.
 18. An assembly as set forth in claim 17 further including a plurality of radially projecting ridges spaced about said base portion and spaced from said neck portion to define a depression for engaging the coil spring.
 19. An assembly as set forth in claim 17 further including a cap at the top of said neck portion to define a jounce contact surface.
 20. An assembly as set forth in claim 17 further including a plurality of strips spaced circumferentially about the exterior of said neck portion and extending axially a predetermined distance spaced from said base portion to a predetermined distance spaced from said jounce contact surface for engaging the coil spring. 